1 MIDI in / 1 MIDI out, USB 1.1;USB bus-powered, Ultra-fast MIDI response;Active-Sensing messages filtered, MME, DirectMusic and CoreMIDI supported;Multiple client support (when used with E-MU Xmidi driver);Compatible with: Microsoft Windows XP SP2 or Vista 32-bit and 64-bit, Intel or AMD CPU - 600MHz or faster, 128MB RAM, 1 USB port, Macintosh: OS X 10.4 or greater, 450MHz G4 or faster, 128MB System RAM, 1 USB port